968 / | HD | HOROLOGY |
580 | PRODUCING ACOUSTIC TIME SIGNALS BY ELECTRICAL MEANS (for mechanical clocks or watches subclasses 225 and 243) [G04C 21/00] {3} | |
581 | DD | .~> Constructional details (subclasses 582 and 588 take precedence) (sound- producing devices in general G10K, e.g., 1/00) [G04C 21/02] |
582 | DD | .~> Indicating the time of the day (acoustic indication of time subclass 217) [G04C 21/04] {2} |
588 | DD | .~> Producing the signals at adjustable fixed times [G04C 21/16] {7} |